TREM2 and Nasu-Hakola disease: Expression of the AD-associated R47H variant and Nasu-Hakola disease (NHD)-associated TREM2 mutants Y38C also strongly reduced the phagocytic activity of TREM2 in HEK293 cells (Figure 1E) mimicking previous observations in microglial cells expressing TREM2 mutations (Kleinberger et al., 2014).